Hypertension is a silent condition and a major contributor worldwide to the growing pandemic of cardiovascular disease and stroke, especially in low- and middle-income countries (LMIC). Of particular importance for LMIC is the presentation at relatively young ages of stroke, one of the many complications from hypertension, thus affecting the health and productivity of the individual, their families, and ther community? Poor control rates for hypertension and a lack of strategies to maintain normal blood pressure, particularly in LMICs, reflect the challenges of effective and affordable implementation in health care and other systems. This proposal aims to estimate the impact of a population-level intervention based on sodium reduction and potassium increase (exchange of ordinary salt for a low-sodium, high-potassium salt substitute) on blood pressure among adults aged 20 years and over. The implementation of this type of strategy must involve all potential participants, from villagers, their families and lcal leaders to local institutions and local, regional and national authorities. Thus, we propose the following specific aims: (1) to assess predisposition patterns towards incorporating the new salt substitute into daily cooking among villagers, authorities and other potential stakeholders, including the feasibility of the implementation; (2) to implement and assess the impact of an intervention using the salt substitute on blood pressure at the population level; and (3) to determine costs and efficacy of this implementation strategy using cost-effectiveness analysis. The intervention component will involve a pragmatic experimental design, the stepped wedge trial design, to progressively implement our intervention at random in several clusters following a period of qualitative exploration and media campaigns. Thus, this study will include qualitative and quantitative methodologies for collecting baseline information to determine potential methods of intervention, while informing the community and a wide range of stakeholders of the strategy. We will then perform the intervention and monitor its effects both during the intervention and at the conclusion. We believe that the organization of involved local stakeholders will provide a strong platform to introduce this innovative intervention and to obtain solid metrics to evaluate its impact. In addition to these methodological strengths, our proposal is innovative because it truly addresses various potential contextual challenges since its conception so that a true implementation effort is tested, with a high likelihood of scaling-up. RELEVANCE: Optimization and initiation of public health strategies to reduce blood pressure levels and hypertension in low and middle income countries (i.e. Peru) will require region-specific approaches that run in parallel with national strategies. The study proposed here will be perhaps the first pragmatic intervention in a Latin- American country to implement a salt substitute at the population level. It will provide important information to develop appropriate local strategies applicable to other resource-constrained settings.